Butt joint for trailer side wall

ABSTRACT

A butt joint assembles side panels of a side wall of a trailer to the base rail of the trailer. The butt joint positions the side panels over the base rail and vertically aligns the outer surfaces of the side panels and the base rail, which provides for an improved trailer side wall.

This application claims the domestic benefit of U.S. ProvisionalApplication Ser. No. 60/884,825 filed on Jan. 12, 2007, which disclosureis hereby incorporated by reference.

FIELD OF THE INVENTION

This invention is generally directed to a butt joint for joining a sidewall of a trailer to a base rail of a trailer.

BACKGROUND OF THE INVENTION

A side wall of a trailer is formed by at least one side panel positionedover a base rail. The at least one side panel forms an upper portion ofthe side wall and is joined with the base rail forming the lower portionof the side wall. The at least one side panel is joined with the baserail using a lap joint such as that shown in FIG. 1. The lap jointincludes a splice member 10 which positions the side panel 12 relativeto the base rail 14. The splice member 10, panel 12, and base rail 14are secured into position using rivets 16. The side panels 12 and baserail 14 are thus stacked on one another or overlapped to form the lapjoint. As a result, an offset is provided at the lap joint and theresulting side wall 8 is not planar. This offset between the side panels12 and the base rail 14 results in a significant bending moment exertedto the lap joint during trailer operation which can result indeformation of the trailer side wall.

The present invention provides a butt joint between the side panels andthe base rail which overcomes the problems presented in the prior artand which provides additional advantages over the prior art, suchadvantages will become clear upon a reading of the attachedspecification in combination with a study of the drawings.

SUMMARY OF THE INVENTION

Briefly, the present invention discloses a butt joint used for assemblyof side panels of a side wall of a trailer to the base rail of thetrailer. The butt joint positions the side panels over the base rail andvertically aligns the outer surfaces of the side panel and the baserail, which provides for an improved trailer side wall.

BRIEF DESCRIPTION OF THE DRAWINGS

The organization and manner of the structure and operation of theinvention, together with further objects and advantages thereof, maybest be understood by reference to the following description, taken inconnection with the accompanying drawings, wherein like referencenumerals identify like elements in which:

FIG. 1 is a cross-sectional view of a prior art lap joint used informing a trailer side wall;

FIG. 2 is a perspective view of a trailer having a side wall formedusing a butt joint which incorporates features of the present invention;

FIG. 3 is an outside perspective view of a portion of a trailer sidewall which incorporates a first embodiment of the butt joint;

FIG. 4 is an inside perspective view of the portion of the trailer sidewall of FIG. 3;

FIG. 5 is an enlarged view of the portion trailer side wall shown inFIG. 4;

FIG. 6 is an elevational end view of an outer element of the butt jointof FIG. 3;

FIG. 7 is an elevational end view of an inner element of the but jointof FIG. 3;

FIG. 8 is a cross-sectional view along line 8-8 of FIG. 3

FIG. 9 is a cross-sectional view of a portion of a side wall of atrailer incorporates a second embodiment of the butt joint;

FIG. 10 is a cross-sectional view of a portion of a side wall of atrailer which incorporates a third embodiment of the joint;

FIG. 11 is a cross-sectional view of a portion of a side wall of atrailer which incorporates a fourth embodiment of the butt joint;

FIG. 12 is a cross-sectional view of a portion of a side wall of atrailer which incorporates a fifth embodiment of the butt joint;

FIG. 13 is a cross-sectional view of a portion of a side wall of atrailer which incorporates a sixth embodiment of the butt joint;

FIG. 14 is a cross-sectional view of a portion of a side wall of atrailer which incorporates a seventh embodiment of the butt joint; and

FIG. 15 is a cross-sectional view of a portion of a side wall of atrailer which incorporates an eighth embodiment of the butt joint.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

While the invention may be susceptible to embodiment in different forms,there is shown in the drawings, and herein will be described in detail,specific embodiments with the understanding that the present disclosureis to be considered an exemplification of the principles of theinvention, and is not intended to limit the invention to that asillustrated and described herein.

A butt joint 50 (shown as reference numeral 50 in FIG. 2, but can alsobe butt joint 100, 200, 300, 400, 500, 600, 700 or 800) is used informing the sidewalls of a trailer 30 as shown in FIG. 2. The trailer 30connects to a tractor (not shown) by conventional means, such as a fifthwheel assembly (not shown). The trailer 30 includes a body formed from apair of rectangular sidewalls 34, a front wall (not shown), a rear door(not shown), a roof 36 formed by at least one top panel 38, and a floorstructure 40. The floor structure 40 is supported by a conventional rearundercarriage assembly 41 and has a landing gear 42 secured thereunder.The sidewalls 34 are formed from a base rail 44 extending from a frontof the trailer to a rear of the trailer and a plurality of side panels46. Each side panel 46 is joined to an adjacent side panel 46 through avertical joint 48 which is known in the art. Alternatively, the sidewall34 can be formed of a continuous sheet. The butt joint 50 connects thelower portions of the side panels 46 to the base rail 44. A bottom rail52 extends from the front of the trailer 30 to the rear of the trailerand joins the base rail 44 to the floor structure 40. A top rail 54extends from the front of the trailer 30 to the rear of the trailer 30and joins the upper ends of the side wall with the roof 36.

The base rail 44 is generally rectangularly-shaped and planar. The baserail 44 has opposite inner and outer surfaces 58, 60, an upper edge 62,a lower edge 64 opposite the upper edge 62, a front edge 66, and a rearedge (not shown) opposite the front edge 66. Due to manufacturingprocesses, the base rail is often cambered or arc-shaped. Thus, theupper edge 62 of the base rail 44, at its center, is curved up or down.Although the base rail can be further processed to eliminate the arc andprovide a planar upper edge 62, such additional processing increases thecost of the trailer.

Each side panel 46 is generally-rectangular and planar. Each side panel46 includes opposite inner and outer surfaces 70,72, an upper edge 74, alower edge 76 opposite the upper edge 74, a front edge 73, and a rearedge 78 opposite the front edge 73. Each side panel 46 is positionedadjacent another side panel 46 such that the rear edge 78 of the firstside panel 46 is adjacent the front edge 73 of an adjacent side panel46. The thickness of each side panel 46 is slightly greater than thethickness of the base rail 44.

As shown in FIG. 3, the side panels 46 are positioned over the base rail44 such that the lower edges 76 of the side panels 46 are proximate theupper edge 62 of the base rail 44. A gap 80 is provided between thelower edges 76 of the side panels 46 and the upper edge 62 of the baserail 44. As noted earlier, the upper edge 62 of the base rail 44 isoften arc-shaped. In such an instance, the height of the gap 80proximate the front and rear edges 66, 68 will vary relative to theheight of the gap 80 proximate the center of the base rail 44. In someinstances, no gap 80 results between the upper edge 62 of the base rail44 and the lower edges 76 of the side panels 46. The side panels 46 andbase rail 44 are further aligned such that the outer surfaces 72 of theside panels 46 and the outer surface 60 of the base rail 44 lie in thesame plane.

The butt joint 50 includes an outer member 82 and an inner member 84spaced from the outer member 82. A channel 86 is provided between theouter an inner members 82, 84 for receiving the side panels 46 and thebase rail 44.

As best shown in FIG. 6, the outer member 82 generally includes an innersurface 88, an outer surface 90, a front end (not shown), a rear end 92,an upper portion 94, a lower portion 96, an upper end 98, a lower end100, and a rail 102. The inner surface 88 is generally planar. Each ofthe upper end 98, lower end 100, and the rail 102 is elongated extendingfrom the front end to the rear end 92 and are generally parallel to eachother. The rail 102 is spaced from the upper and lower ends 98, 100 andextends outwardly. The rail 102 has a generally arc-shaped cross-sectionextending from the outer surface 90 such that the rail 102 provides athickened portion of the outer member 82. The upper end 98 has agenerally annularly-shaped cross-section and extends from the upperportion 94. The lower end 100 provides a generallysemi-circularly-shaped cross-section and extends from the outer surface90 proximate the lower portion 96. The upper portion 94 extends from therail 102 to the upper end 98 and from the front end of the outer member82 to the rear end 92. The lower portion 96 extends from the rail 102 tothe lower end 100 and from the front end of the outer member 82 to therear end 92.

Apertures are provided at spaced apart positions along the length of theouter member 82 between the upper end 98 and the rail 102. Apertures areprovided at spaced apart positions along the length of the outer member82 between the lower end 100 and the rail 102. Each aperture extendsfrom the outer surface 90 to the inner surface 88 of the outer member82.

The inner member 84 generally includes an inner surface 104, an outersurface 106, a front end 108, a rear end (not shown), an upper portion110, a lower portion 112, an upper end 114, a lower end 116 and a rail118. Each of the upper end 114, lower end 116, and rail 118 extends fromthe front end 108 to the rear end of the inner member 84 and aregenerally parallel to each other. The rail 118 is spaced from the upperand lower ends 114, 116 and extends inwardly from the inner surface 104.The rail 118 extends inwardly from the inner surface 104 and has agenerally arc-shaped cross-section such that the rail 118 provides athickened portion of the inner member 84. The lower portion 112 extendsfrom the rail 118 to the lower end 116, and from the front end 108 tothe rear end of the inner member 84. The upper portion 110 extends fromthe rail 118 to the upper end 114, and from the front end 108 to therear end of the inner member 84. Upper and lower portions 110, 112 areoffset. Accordingly, the outer surface 106 of the upper portion 110 ispositioned inwardly (relative to the interior of the trailer) of theouter surface 106 of the lower portion 112.

Apertures are provided at spaced apart positions along the length of theinner member 84 between the lower end 116 and the rail 118. Aperturesare provided at spaced apart positions along the length of the innermember 84 between the rail 118 and the upper end 114. Each apertureextends from the inner surface 104 to the outer surface 106 of the innermember 84.

As best shown in FIG. 8, the channel 86 is defined between the outermember 82 and the inner member 84 when the outer and inner members 82,84 are faced towards each other, but are spaced apart a distance equalto the width of the side wall 34. More specifically, the channel 86 isdefined by the inner surface 88 of the outer member 82 and the outersurface 106 of the inner member 84. The channel 86 includes an upperportion 122 provided between the inner surface 88 of the upper portion94 of the outer member 82 and the outer surface 106 of the upper portion110 of the inner member 84, a lower portion 124 provided between aninner surface 88 of the of the lower portion 96 of the outer member 82and the outer surface 106 of the lower portion 112 of the inner member84, and a transition portion 126 provided between the inner surface 88of the rail 102 of the outer member 82 and the outer surface 106 of therail 118 of the inner member 84. As shown, the width of the upperportion 122 of the channel 86 is greater than the width of the lowerportion 124 of the channel 86.

The side panels 46 are positioned in the upper portion 122 of thechannel 86 and the base rail 44 is positioned in the lower portion 124of the channel 86 such that the gap 80 between the lower edge 76 of theside panels 46 and the upper edge 62 of the base rail 44 is positionedin the transition portion 126 of the channel 86. The outer surfaces 72of the side panels 46 abut the inner surface 88 of the upper portion 94of the outer member 82 and the inner surfaces 70 of the side panels 46abut the outer surface 106 of the upper portion 100 of the inner member84. The outer surface 60 of the base rail 44 abuts the inner surface 88of the lower portion 96 of the outer member 82 and the inner surface 58of the base rail 44 abuts the outer surface 106 of the lower portion 112of the inner member 84. The planar nature of the inner surface 88 of theouter member 82 provides planar positioning of the outer surfaces 72 ofthe side panels 46 with the outer surface 60 of the base rail 44. Asshown, the width of the side panel 46 is greater that the width of thebase rail 44. The upper portion 122 of the channel 86 is therefore widerthan the lower portion 124 of the channel 86 to accommodate the sidepanels 46 which have a greater width than the base rail 44. If sidepanel 46 does not have a width which is greater than the width of thebase rail 44, the upper portion 122 of the channel 86 is not wider thanthe lower portion 124 of the channel 86.

As best shown in FIGS. 3-5, fasteners 130 are provided through theapertures of the upper portion 94 of the outer member 82, through theside panels 46 and through the apertures of the upper portion 110 of theinner member 84 to secure the outer and inner members 82, 84 to the sidepanels 46. Fasteners are also provided through the apertures of thelower portion 96 of the outer member 82, through the base rail 44 andthrough the apertures of the lower portion 112 of the inner member 84 tosecure the outer and inner members 82, 84 to the base rail 44. A buttjoint 50 is therefore formed between the side panels 46 and the baserail 44. It is to be understood that alternative means, such as,adhesives could be used to secure the outer and inner members 82, 84 tothe side panels 46 and base rail 44, or, a combination of fasteners andadhesives could be used to secure the outer and inner members 82, 84 tothe side panels 46 and base rail 44. If only adhesives are used tosecure the members 82, 84 then the apertures will be removed from theouter and inner members 42, 44.

By removing the offset as found in the prior art, See FIG. 1, andproviding vertical alignment of the outer surfaces 60, 72 of the baserail 44 and the side panels 46, a bending moment exerted to the buttjoint 50 during operation of the trailer is minimized. In addition, theouter and inner members 82, 84 act as structural members of the sidewall34 capable of carrying shear and bending forces. Thus, the structuralintegrity of the sidewall 34 is improved by the butt joint 50.Furthermore, the butt joint 50 provides for an improved load capacityand improved floor strength capacity. The butt joint 50 also providesfor simplified assembly of the trailer, lowers the tare weight of thetrailer and lowers the manufacturing costs.

The rail 102 of the outer member 82 and the rail 118 of the inner member84 carry vertical compressive forces acting on the butt joint 50 andprevent the outer and inner members 82, 84 from deforming as a result ofsuch forces.

When the outer member 82 is positioned proximate the side panels 46, acavity 132 (see FIG. 8) is defined between the upper end 98 and theouter surfaces of the side panels 46. An adhesive/sealant is placed inthe cavity 132 to prevent moisture from entering the trailer through thebutt joint 50. Furthermore, in the event fasteners 130 are used inassembling the butt joint 50 with the panels 46 and the base rail 44,the rails 102, 118 provide protection to the fasteners 130. The rails102, 118 prevent shearing off of the fasteners 130 in the event thetrailer rubs against another trailer or in the event cargo or equipmentused to load cargo rubs along the interior of the trailer side wall.Such protection results in lower equipment maintenance cost.

A second embodiment of the butt joint 200 is shown in FIG. 9. The buttjoint 200 includes an outer member 202 and an inner member 204 which aresimilar to the outer and inner members 82, 84 of the butt joint 50, withthe following exceptions.

The outer member 202 includes an inwardly extending tongue 206. Thetongue 206 extends opposite the rail 102 and is generally perpendicularto the inner surface 88 of the outer member 202. The tongue 206 extendsfrom the front end to the rear end 92 of the outer member 202. Unlikethe lower end 100 of the outer member 82 which provides a generallysemi-circularly shaped cross-section, the lower end 215 of the outermember 202 provides an arc-shaped cross-section.

The inner member 204 includes an upper flange 208 and a lower flange210, each extending outwardly opposite the rail 118. The upper and lowerflanges 208, 210 extend from the front end to the rear end of the innermember 204. The upper and lower flanges 208, 210 generally extendperpendicular to the inner surface 104 of the inner member 204. A slotis provided between the upper and lower flanges 208, 210. A sealantcavity 218 is provided by the upper edge 114 of the inner member 204 anda sealant cavity 220 is provided by the lower edge 116 of the innermember 204.

When the butt joint 200 is assembled with the side panels 46 and thebase rail 44, the tongue 206 of the outer member 202 extends within theslot provided between the upper and lower flanges 208, 210 of the innermember 204. The interengaged tongue 206 and flanges 208, 210 provide abridge between the outer member 202 and the inner member 204 whichseparates the upper portion 122 of the channel 86 from the lower portion124 of the channel 86. As shown, the width of the upper portion 122 ofthe channel 86 is greater than the width of the lower portion 124 of thechannel 86.

The side panels 46 are positioned in the upper portion 122 of thechannel 86. The lower edge of each side panel 46 contacts an uppersurface of the upper flange 208.

The base rail 44 is positioned in the lower portion 124 of the channel86. Portions of the upper edge of the base rail 44 abut the lowersurface of the lower flange 210. As noted earlier, the height of thebase rail 44 may be greater at its center than the height of the baserail 44 proximate its front and rear edges 66, 68. Thus, it is likelythe base rail 44 will contact the lower surface of the lower flange 210proximate the center of the base rail 44, and a gap will remain betweenthe base rail 44 and the lower surface of the lower flange 210.

The planar nature of the inner surface 88 of the outer member 202 of thebutt joint 200 provides planar positioning of the outer surfaces of theside panels 46 and base rail 44. The widths of the upper and lowerportions 122, 124 of the channel 86 are determined based upon respectivewidths of the side panels 46 and base rail 44 to be positioned withinthe channel 86. As shown, the width of the side panels 46 is greaterthan the width of the base rail 44 and, therefore, the upper portion 122of the channel 86 is wider than the lower portion 124 of the channel 86.It is to be understood that if the width of the side panel 46 was notgreater than the width of the base rail 44, the upper portion 122 of thechannel 86 would not be wider than the lower portion 124 of the channel86.

In addition to providing support for vertical compressive forces, theflanges 208, 210 assist in aligning the side panels 46 and base rail 44within the channel 86 prior to fastening.

A third embodiment of the butt joint 300 is shown in FIG. 10. The buttjoint 300 is identical to the butt joint 50 shown in FIG. 9 except forthe following. Rather than a single inwardly extending tongue, the outermember 302 of the butt joint 300 includes upper and lower inwardlyextending flanges 304, 306. Rather than two outwardly extending flanges,the inner member 308 includes a single outwardly extending tongue 310.When assembled, the tongue 310 of the inner member 308 extends withinthe gap provided between the upper and lower flanges 304, 306 of theouter member 302. The interengaged tongue 310 and flanges 304, 306provide a bridge between the outer member 302 and the inner member 308.

As shown, the upper and lower portions 122, 124 of the channel 86 havethe same width. The portions 122, 124 of the channel 86 can of course bemodified to accept panels 46 and base rails 44 having varying widths.

A fourth embodiment of the butt joint 400 is shown in FIG. 11. The buttjoint 400 includes an outer member 402 and an inner member 404 spacedfrom and connected to the outer member 402 by a bridge 403. The outermember 402, inner member 404 and bridge 403 are integrally formed. Achannel 406 is provided between the outer and inner members 402, 404 forreceiving the side panels 46 and the base rail 44.

The outer member 402 generally includes an inner surface 408, an outersurface 410, a front end (not shown), a rear end (not shown), an upperportion 412, a lower portion 414, an upper end 416 extending from theupper portion 412, and a lower end 418 extending from the lower portion414. The inner surface 408 is generally planar. The upper end 416 andthe lower end 418 are elongated, extend from the front end to the rearend, and are generally parallel to each other. The upper and lower ends416, 418 have a generally annularly-shaped cross-section. The upperportion 412 extends from the bridge 403 to the upper end 416 and fromthe front end of the outer member 402 to the rear end. The lower portion414 extends from the bridge 403 to the lower end 418 and from the frontend of the outer member 402 to the rear end.

Apertures are provided at spaced apart positions along the length of theouter member 402 between the upper end 416 and the bridge 403. Aperturesare provided at spaced apart positions along the length of the outermember 402 between the lower end 418 and the bridge 403. Each apertureextends from the outer surface 410 to the inner surface 408 of the outermember 402.

The inner member 404 generally includes an inner surface 420, an outersurface 422, a front end (not shown), a rear end (not shown), an uppertab 424, a lower portion 426, and a lower end 428. The lower end 428extends from the front end to the rear end of the inner member 404. Thelower portion 426 extends from the bridge 403 to the lower end 428, andfrom the front end to the rear end of the inner member 404. The uppertab 424 extends upwardly from the bridge 403, and from the front end tothe rear end of the inner member 404. The upper tab 424 and the lowerportion 426 are offset. Accordingly, the outer surface 422 of the uppertab 424 is positioned inwardly (relative to the interior of the trailer)of the outer surface 422 of the lower portion 426.

Apertures are provided at spaced apart positions along the length of theinner member 404 between the lower end 428 and the bridge 403. Theapertures extend from the inner surface 420 to the outer surface 422 ofthe inner member 404.

The channel 406 is defined between the outer member 402 and the innermember 404 More specifically, the channel 406 is defined by the innersurface 408 of the outer member 402 and the outer surface 422 of theinner member 404. The channel 406 includes an upper portion 406 aprovided between the inner surface 408 of the upper portion 412 of theouter member 402 and the outer surface 422 of the upper tab 424 of theinner member 404, and a lower portion 406 b provided between an innersurface 408 of the lower portion 414 of the outer member 402 and theouter surface 422 of the lower portion 426 of the inner member 404. Thewidth of the upper portion 406 a of the channel 406 is greater than thewidth of the lower portion 406 b of the channel 406.

The side panels 46 are positioned in the upper portion 406 a of thechannel 406 such that the lower edge of the side panel 46 contacts anupper surface of the bridge 403. The base rail 44 is positioned in thelower portion 406 b of the channel 406 such that at least a portion ofthe upper end of the base rail 44 contacts a lower surface of the bridge403. The outer surfaces 72 of the side panels 46 abut the inner surface408 of the upper portion 412 of the outer member 402 and the innersurfaces 70 of the side panels 46 abut the outer surface 422 of theupper tab 424 of the inner member 404. The outer surface 60 of the baserail 44 abuts the inner surface 408 of the lower portion 414 of theouter member 402 and the inner surface 58 of the base rail 44 abuts theouter surface 422 of the lower portion 426 of the inner member 404. Theplanar nature of the inner surface 408 of the outer member 402 providesplanar positioning of the outer surfaces 72 of the side panels 46 withthe outer surface 60 of the base rail 44. As shown, the width of theside panel 46 is greater that the width of the base rail 44. The upperportion 406 a of the channel 406 is therefore wider than the lowerportion 406 b of the channel 406 to accommodate the side panels 46 whichhave a greater width than the base rail 44. If side panel 46 does nothave a width which is greater than the width of the base rail 44, theupper portion 406 a of the channel 406 will not be formed wider than thelower portion 406 b of the channel 406.

Fasteners 430 are provided through the apertures of the upper portion412 of the outer member 402 and through the side panels 46 to secure theouter members 402 to the side panels 46. Fasteners are also providedthrough the apertures of the lower portion 414 of the outer member 402,through the base rail 44 and through the apertures of the lower portion426 of the inner member 404 to secure the outer and inner members 402,404 to the base rail 44. The butt joint 400 is therefore formed betweenthe side panels 46 and the base rail 44. It is to be understood thatalternative means, such as, adhesives could be used to secure the outerand inner members 402, 404 to the side panels 46 and base rail 44, or acombination of fasteners and adhesives could be used to secure the outerand inner members 402,404 to the side panels 46 and base rail 44. Ifonly adhesives are used to secure the members 402, 404 then theapertures will be removed from the outer and inner members 402, 404.

Similar to the butt joint 50, by removing the offset as found in theprior art, see FIG. 1, and providing vertical alignment of the outersurfaces 60, 72 of the base rail 44 and the side panels 46, a bendingmoment exerted to the butt joint 400 during operation of the trailer isminimized. In addition, the outer and inner members 402, 404 act asstructural members of the sidewall 34 capable of carrying shear andbending forces. Thus, the structural integrity of the sidewall 34 isimproved by the butt joint 400. Furthermore, the butt joint 400 providesfor an improved load capacity and improved floor strength capacity. Thebutt joint 400 also provides for simplified assembly of the trailer,lowers the tare weight of the trailer and lowers the manufacturingcosts.

When the outer member 402 is positioned proximate the side panels 46 andbase rail 44, a cavity 432 is defined between the upper end 416 and theouter surfaces of the side panels 46 and a cavity 434 is defined betweenthe lower end 418 and the outer surface of the base rail 44. When theinner member 404 is positioned proximate the base rail 44 a cavity 436is defined between the lower end 428 and the outer surface 58 of thebase rail 44. An adhesive/sealant is placed in the cavities 432, 434,436 to prevent moisture from entering the trailer through the butt joint400.

A fifth embodiment of the butt joint 500 is shown in FIG. 12. The buttjoint 500 is identical to the butt joint 400 shown in FIG. 11 except forthe following features. Rather than providing an upper tab 424 on theinner member 404, an inner member 504 of the butt joint 500 includes anupper portion 525 which is approximately the same length as the upperportion 412 of the outer member 402. The inner member 505 furtherincludes an elongated inwardly extending rail 510 which extends from thefront of the inner member 504 to the rear of the inner member 504. Theinnermost surface 510 a of the rail 510 is generally planar and parallelto the side panel 46 and base rail 44. A first inclined surface 510 bextends from the inner most surface 510 a to the upper portion 525 ofthe inner member 504 and a second inclined surface 510 c extends fromthe inner most surface 510 a to a lower portion 526 of the inner member504.

A sixth embodiment of the butt joint 600 is shown in FIG. 13. The buttjoint 600 includes an outer member 602 and an inner member 604. The buttjoint 600 is similar to the butt joint 400 of FIG. 11 with the followingexceptions. The tab 424 of the butt joint 400 is replaced with an upperportion 608 of the inner member 604, and the upper portion of the outermember 412 of the butt joint 400 is replaced with a tab 606. Thus, theinner surface 605 of the tab 608 and the inner surface 603 of a lowerportion 607 of an outer member 602 are planar and the outer surface 609of the upper portion 608 of the inner member 604 is off set from theouter surface 611 of the lower portion 610 of the inner member 604.

A seventh embodiment of the butt joint 700 is shown in FIG. 14. The buttjoint 700 is generally formed by an outer member 702 and a base rail 705having an offset upper portion 720. The portions of the base rail 705proximate to the outer member 702 form the inner member. The outermember 702 generally includes an inner surface 704, an outer surface706, a front end (not shown), a rear end (not shown), an upper portion708, a lower portion 710, an upper end 712, a lower end 714, a rail 716,and a tongue 718. The inner surface 704 of the outer member 702 isgenerally planar. The upper end 712, the lower end 714, the rail 716,and the tongue 718 extend from the front end of the outer member 702 tothe rear end of the outer member 702 and are generally parallel to eachother. The tongue 718 extends inwardly and is positioned opposite therail 716. The rail 716 is elongated and extends from the front end tothe rear end of the outer member. The rail 716 includes first planarsurface 716 which is generally parallel to the inner surface 704 of theouter member 702, a second inclined surface 716 b which extends inwardlyfrom the first surface 716 of the upper portion 708, and a thirdinclined surface 716 c which extends inwardly from the first surface 716a to the lower portion 710. The upper portion 708 of the outer member702 extends from the rail 716 to the upper end 712 and from the frontend of the outer member 702 to the rear end of the outer member 702. Thelower portion 706 of the outer member 702 extends from the rail 716 tothe lower end 714 and from the front end of the outer member 702 to therear end of the outer member 702.

Apertures are provided at spaced apart positions along the length of theouter member 702 between the upper edge 712 and the rail 716. Aperturesare also provided at spaced apart positions along the length of theouter member 702 between the lower edge 714 and the rail 716. Eachaperture extends from the outer surface 706 of the outer member 702 tothe inner surface 704 of the outer member 702.

The base rail 705 includes the offset upper portion 720, a lower portion722, a transition portion 724 between the upper and lower portions 720,722, an inner surface 729, an outer surface 730, and front and rear ends(not shown). The upper portion 720 is offset from the lower portion 722such that the upper portion 720 is positioned inwardly relative to thelower portion 722. The lower portion 722 of the base rail 705 isparallel to the inner surface 704 of the outer member 702 and is incontact with the inner surface 704. The upper portion 720 of the baserail 705 is parallel to the inner surface 704 of the outer member 702,but is spaced from the inner surface 704. The transition portion 724 ofthe base rail 705 extends inwardly and upwardly from the upper edge ofthe lower portion 722 to the lower edge of the upper portion 720. Whenplaced between the outer member 702 and the inner member 704, a channel728 is defined by the inner surface 704 of the outer member 702 and theouter surface 730 of the upper portion 720 of the base rail 705. Thetongue 718 of the outer member 702 contacts the upper portion 720 of thebase rail 705 proximate the transition portion 724.

Apertures are provided at spaced apart positions through the upper andlower portions 708, 710 of the outer member 702. Apertures are providedat spaced apart positions through the upper and lower portions 720, 722of the base rail 705 and are aligned with the apertures of the outermember 702.

When assembled with the side panels 46, the outer surfaces 72 of theside panels 46 contact the inner surface 704 of the outer member 702;the inner surfaces 70 of the side panels 46 contact the outer surface730 of the upper portion 720 of the base rail 705; and the lower edges76 of the side panels 46 contact an upper surface of the tongue 718.

Fasteners 732 are provided through the apertures in the upper portion708 of the outer member 702, through the side panels 46 and through theapertures of the upper portion 720 of the base rail 705 to secure theouter member 702 and the base rail 705 to the side panels 46. Fasteners732 are provided through the apertures of the lower portion 706 of theouter member 702 and through the lower portion 722 of the base rail 705to secure the outer member 702 to the base rail 705. The butt joint 700is provided between the side panels 46 and the lower portion 722 of thebase rail 705. It is to be understood that alternative means, such as,for example adhesives could be used to secure the outer member 702 tothe side panels 46 and base rail 705 and to secure the side panels 46 tothe base rail 705 and the apertures eliminated. In addition, acombination of fasteners and adhesives can be used to secure the outermember 702 to the side panels 46 and base rail 705 and to secure theside panels 46 to the base rail 705.

The butt joint 700 provides vertical alignment between the outer surface72 of the side panel 46 and the outer surface 730 of the lower portion722. By removing the offset as found in the prior art, a bending momentexerted on the butt joint 700 during operation of the trailer isminimized. In addition, the outer member 702 acts as a structural memberof the side wall 34 capable of carrying sheer and bending forces. Thebutt joint 700 also provides for simplified assembly of the trailerlowers the tare weight of the trailer and lowers the manufacturingcosts.

The rail 716 of the outer member 702 carries vertical compressive forcesacting on the butt joint 700 and prevents the outer member 702 fromdeforming as a result of such forces.

When the outer member 702 is positioned proximate the side panels 46, acavity 734 is defined between the upper end 712 and the outer surface 72of the side panel 46. An adhesive/sealant is placed in the cavity 734 toprevent moisture for entering the trailer through the butt joint 700.Furthermore, in the event fasteners are used in assembling the buttjoint 700, the panels 46, the rail 716 provides protection to thefasteners 732 to prevent shearing off of the fasteners 732.

An eighth embodiment of the butt joint 800 is shown in FIG. 15. The buttjoint 800 includes an outer member 802 and a base rail 805 having anoffset upper portion 805. The butt joint 800 is identical to the buttjoint 700 shown in FIG. 14 with the following exception. The outermember 702 of the butt joint 700 has an inwardly extending tongue 718opposite the rail 716 which extends across the channel 728. In contrast,the outer member 802 of the butt joint 800 includes a tooth 818extending into the channel between the outer member 802 and the baserail 805, but does not contact the base rail 805. The tooth 818 providesassistance to align the outer member 802 with the side panel 46 whenassembling the outer member 802, side panel 46 and base rail 805.

While preferred embodiments of the present invention are shown anddescribed, it is envisioned that those skilled in the art may devisevarious modifications of the present invention without departing fromthe spirit and scope of the appended claims.

1. A sidewall of a trailer comprising: a side panel; a base rail; aninner member having an inner surface and an outer surface; an outermember spaced from said inner member, said outer member having agenerally planar inner surface and an outer surface; and a channelhaving upper and lower portions defined by said outer surface of saidinner member and said inner surface of said outer member, said lowerportion of said channel positioned beneath said upper portion of saidchannel, said side panel positioned within said upper portion of saidchannel and said base rail positioned within said lower portion of saidchannel.
 2. A sidewall as defined in claim 1, wherein said outer surfaceof said inner member includes an upper portion and a lower portion andsaid upper portion is offset from said lower portion.
 3. A sidewall asdefined in claim 1, wherein a width of said upper portion of saidchannel is greater than a width of said lower portion of said channel.4. A sidewall as defined in claim 1, wherein a rail is provided on saidouter surface of said outer member.
 5. A sidewall as defined in claim 1,wherein a rail is provided on said inner surface of said inner member.6. A sidewall as defined in claim 1, wherein said outer member furtherincludes at least one protrusion extending from and generallyperpendicular to said inner surface of said outer member, said inwardlyextending protrusion positioned between said upper and lower portions ofsaid channel.
 7. A sidewall as defined in claim 6, wherein said innermember further includes at least one protrusion extending from andgenerally perpendicular to said inner surface of said outer member, saidprotrusion on said inner member positioned between said first and secondportions of said channel, and said protrusion on said inner member isengaged with protrusion of said outer member.
 8. A sidewall as definedin claim 7, wherein said inner member includes two protrusions and saidprotrusion of said outer member is positioned between said twoprotrusions.
 9. A sidewall as defined in claim 7, wherein said outermember includes two protrusions and wherein said of said inner member ispositioned between said two inwardly extending protrusions.
 10. Asidewall as defined in claim 1, further comprising a bridge extendingbetween said outer surface of said inner member and said inner surfaceof said outer member and positioned between said upper and lowerportions of said channel.
 11. A sidewall as defined in claim 10, whereinsaid inner wall, said outer wall, and said bridge are integrally formed.12. A sidewall as defined in claim 1, wherein said outer member furtherincludes an upper portion defining said upper portion of said channel,said inner member further includes and upper portion defining said upperportion of said channel and a length of said upper portion of said outermember is greater than a length of an upper portion of the inner member.13. A sidewall as defined in claim 1, wherein said outer member furtherincludes an upper portion defining said upper portion of said channel,said inner member further includes an upper portion defining said upperportion of said channel and a length of said upper portion of said innermember is greater than the a length of an upper portion of said innermember.
 14. A sidewall as defined in claim 1, wherein an adhesive cavityis provided by an upper end of said outer member.
 15. A sidewall asdefined in claim 1, wherein said inner and outer member are secured tothe side panel and base rail using fasteners.
 16. A sidewall as definedin claim 1, wherein said inner and outer member are secured to the sidepanel and base rail using adhesive.
 17. A sidewall of a trailercomprising: a side panel; an outer member having a planar inner surface;a base rail having an upper portion offset from a lower portion, anouter surface of said upper portion of said base rail is generallyparallel to and spaced from said inner surface of said outer member; achannel defined by an outer surface of said upper portion of said baserail and said inner surface of said outer member, said side panel beingpositioned within said channel; and said lower portion of said base railis positioned beneath said channel.
 18. A sidewall as defined in claim17, wherein said outer member further includes a rail.
 19. A sidewall asdefined in claim 17, wherein said outer member includes a protrusionpositioned above said lower portion of said base rail and extendinginwardly.
 20. A sidewall as defined in claim 19, wherein said protrusionextends to an inner surface of said base rail.
 21. A sidewall as definedin claim 19, wherein said outer member further includes an adhesivecavity.
 22. A sidewall as defined in claim 19, wherein said outer memberis secured to said base rail using fasteners.
 23. A sidewall as definedin claim 19, wherein said outer member is secured to said base railusing adhesive.